Abstract
Despite the development of several new polymeric materials for CO2 capture membranes such as thermally rearranged polymers (TR), polymers with intrinsic microporosity (PIM), hybrid polymer-inorganics systems containing metal-organic frameworks (MOFs), zeolites and nanoparticles, only few membranes have arrived at the stage of testing at pilot scale due to good separation properties combined with durability and easiness in manufacturing. In general, these membranes separate gasses according to solution diffusion mechanism (SD).
The water vapours inherently present in all gas streams containing CO2, from biogas to flue gas or natural gas, favours the use of a class of polymeric membranes containing specific "carriers" that react reversibly with CO2 in presence of water and which separate gasses based on facilitation transport (FT).
The membranes reported in the present work combines the best properties of SD membranes (high CO2 permeability but low selectivity) with FT membranes (moderate CO2 permeability but high selectivity) in a hybrid integrated (HI) concept.
Our approach is based on modifying in precise and controlled manner the membrane surfaces with CO2 reactive groups leading to ultrathin CO2 selective surface layer. The developed membrane integrates this highly selective top layer of surface-grown polyamines into a highly permeable but low selective membrane in a concept called “hybrid-integrated membrane”.
The uniformity of surface grafting plays a major role on separation properties and is dependent on grafting conditions. Excessive crosslinking due to some grafting conditions and certain monomers reduced the expected CO2 permeance and needed to eliminate.
The structural characterization is correlated with the results from mixed gas permeation testing using a synthetic flue gas: 10 % CO2 in N2, fully humidified.
Excellent gas permeation results were obtained with CO2 permeabilities in excess of 1000 Barrer and CO2/N2 selectivity up to 150-fold higher than reference unmodified membranes.
References
[1] Marius Sandru, E. M. Sandru, W. F. Ingram, J.Deng, P.M. Stenstad, L. Deng, R.J. Spontak, An integrated materials approach to ultrapermeable and ultraselective CO2 polymer membranes, Science 376 (6588), 90-94 (2022)
[2] M. Sandru et al., Composite hollow fiber membranes for CO2 capture, J. of Membrane. Sci. 346 (2010), 172-186
Acknowledgements
This study was supported by the Research Council of Norway through the POLYMEM project (Grant No. 254791) in the CLIMIT program and UEFSCDI Romania through the CO2Hybrid project (Grant No. 13/2020) and the National Science Foundation through the North Carolina Research Triangle Nanotechnology Network (grant no. ECCS-2025064)
The water vapours inherently present in all gas streams containing CO2, from biogas to flue gas or natural gas, favours the use of a class of polymeric membranes containing specific "carriers" that react reversibly with CO2 in presence of water and which separate gasses based on facilitation transport (FT).
The membranes reported in the present work combines the best properties of SD membranes (high CO2 permeability but low selectivity) with FT membranes (moderate CO2 permeability but high selectivity) in a hybrid integrated (HI) concept.
Our approach is based on modifying in precise and controlled manner the membrane surfaces with CO2 reactive groups leading to ultrathin CO2 selective surface layer. The developed membrane integrates this highly selective top layer of surface-grown polyamines into a highly permeable but low selective membrane in a concept called “hybrid-integrated membrane”.
The uniformity of surface grafting plays a major role on separation properties and is dependent on grafting conditions. Excessive crosslinking due to some grafting conditions and certain monomers reduced the expected CO2 permeance and needed to eliminate.
The structural characterization is correlated with the results from mixed gas permeation testing using a synthetic flue gas: 10 % CO2 in N2, fully humidified.
Excellent gas permeation results were obtained with CO2 permeabilities in excess of 1000 Barrer and CO2/N2 selectivity up to 150-fold higher than reference unmodified membranes.
References
[1] Marius Sandru, E. M. Sandru, W. F. Ingram, J.Deng, P.M. Stenstad, L. Deng, R.J. Spontak, An integrated materials approach to ultrapermeable and ultraselective CO2 polymer membranes, Science 376 (6588), 90-94 (2022)
[2] M. Sandru et al., Composite hollow fiber membranes for CO2 capture, J. of Membrane. Sci. 346 (2010), 172-186
Acknowledgements
This study was supported by the Research Council of Norway through the POLYMEM project (Grant No. 254791) in the CLIMIT program and UEFSCDI Romania through the CO2Hybrid project (Grant No. 13/2020) and the National Science Foundation through the North Carolina Research Triangle Nanotechnology Network (grant no. ECCS-2025064)